Milpitas in general is more affordable than most areas of Sunnyvale. This particular group of homes is also pretty close to a jail. When I first got my license, I can remember looking at these homes (they were nearly brand new) and one of my colleagues was a native of Milpitas. She joked "they almost never have breakouts" and described this area as one of the least desirable in Milpitas by the long term residents.
I personally love Milpitas! So it is a matter of over-arching desirability. Milpitas has very good elementary and middle schools, and an OK high school. Some advantages to Milpitas include good shopping (Great Mall, McCarthy Ranch), movies, access to 680 and 880 and 237 for ease of commute, and a brand new library near Main/Calaveras. It is easy to navigate Milpitas! I board my horse in the foothills of Milpitas up Calaveras Road.
Sunnyvale, however, has long been considered more desirable. They do have newer townhouses in a similar price range in 94085. Sunnyale has a heirarchy of zip codes, with 94087 being the most expensive (close to Cupertino and Los Altos, some Cupertino school enrollment areas); 94086 next (some Sunnyvale school district boundaries, other schools are Santa Clara Unified); then 94085 (in general, closer to 101/Fair Oaks and Lockheed) and then 94089 (least expensive area, other side of 101).
Santa Clara is a relatively affordable area, although the prices are not as affordable as Milpitas. Santa Clara features wonderful libraries and a good city center. It's easy to get anywhere! In general, Santa Clara Unified is not considered as strong as neighboring school districts.
We see the quality of schools being an integrated factor related to pricing throughout the South Bay, with homes that feed into excellent schools, in general, being more expensive and becoming increasingly so as you get into Palo Alto (where I grew up).
Another area that is relatively inexpensive is the North San Jose area adjacent to Milpitas, this area, called North Valley by residents, has decent schools and more affordable (but few new) homes. You can also find newer homes in area of Fremont for decent pricing, but as you get into the great school district areas (Mission) you can't get as good of pricing!
Good luck in your search!
Erica M Nelson